The present invention relates to a method and apparatus for the uniform and simultaneous illumination by means of radiation of the interior surfaces of cavities for the purpose of observing and/or treating the interior surfaces.
In multilocularly growing tumors, e.g. bladder carcinoma, there often exist, in addition to marcroscopically detectable tumor sites, minute microscopic tumor regions. Since it was impossible in the past to detect the latter with conventional therapy procedures (e.g. "Der Urologe" [The Urologist], Edition B, Volume 21, No. 3, June 1981), about 50% of the cases of, for example, bladder carcinoma, manifest themselves within 15 months after first treatment. These are the so-called recurring tumors.
Previously used therapy procedures in connection with bladder carcinoma include transurethral resection, partial bladder resection, and tumor coagulation by means of electrical current or laser radiation (Nd-YAG, argon laser). Local infusion of cell multiplication inhibitors in the bladder have been able to reduce the recurrence rate of surface growing tumors by a maximum of 30%. However, neither the use of local hyperthermia, a procedure that is still in the experimental state, nor the use of ionizing radiation have brought significant improvements.
It is also known (see, e.g., Journal of Urology, Volume 115, February 1976, pages 150-151) to make tumors growing on the interior walls of organ cavities selectively sensitive to light, i.e. to photosensitize them, by dispensing suitable chemical substances, such as hematoporphyrin derivative (HpD), hematoporphyrin, porphyrin, tetracycline, acridine orange, etc. Subsequent irradiation with suitable light, for example red (laser) light for HpD, then leads to photochemical reactions in the photosensitized tissue, resulting ultimately in destruction of the tumor tissues. Normal, nonphotosensitized tissue, however, is not damaged by the low energy light irradiation.
In industry as well, particularly in the motor vehicle construction art, problems arise if cavities that are inaccessible or very difficultly accessible in articles are to be detected, observed and/or irradiated in order to seal them. The same problems exist in the conservation art if, for example, cavities in archeological or historically valuable buildings or articles are to be sealed to protect them against further decay or for reasons of stability.